JPH11120684A - Disk drive device, disk discriminating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate the class, etc., of an optical disk to be loaded by detecting the information of reflected light of a laser beam while making an objective lens forcibly move in the state set to a 2nd gain value corresponding to the disk of 2nd kind and discriminating the level of a specified signal of reflected light information from a process means of reflected light information in the moving period of the objective lens. SOLUTION: A discriminating signal DD is produced by a discrimination processing part 16 from an RF signal level corresponded to the class of disk or the existence of disk. By a discriminating signal producing circuit 14, the discriminating signal DD resulting from the discrimination as to the disk of 1st kind, the disk of 2nd kind and no existence of disk is supplied to a system controller 10. When the disk is discriminated as the 2nd kind in the discrimination result, the focus search process is started to execute the driving of the objective lens. When the disk is discriminated as the 1st kind, the set gain in an RF matrix amplifier 9 is changed over to the gain G1 at first, and after that, the focus search process is started.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a disk drive device capable of performing a reproducing or recording operation corresponding to a plurality of types of disk-shaped recording media, and a disk discriminating method.

[0002]

2. Description of the Related Art As an optical disk recording medium, a CD (compact disk-digital audio, hereinafter referred to as CD-DA) is used.
Is widely spread and used for music purposes. A CD-DA for music is usually a read-only medium, but a write-once disc called a CD-R (compact disc-recordable) has also been developed.
Further, a disk called a CD-RW (compact disk-rewritable) capable of rewriting data has been developed as a disk suitable for multimedia applications. CD-
The RW is a so-called phase change medium.

[0003] These discs are all of the same size (diameter: 12 cm), and a substantially similar pickup can be used as an optical recording / reproducing method, so that any of these three types of discs can be used. Drive devices have been developed.

[0004]

By the way, CD-D
In a disk drive device capable of handling a plurality of types of disks such as A, CD-R, and CD-RW, it is also necessary to switch the operation according to the disk type as the recording / reproducing operation. For example, CD-RW is CD-DA, CD
Since the reflectivity is lower than that of -R, the loaded disc is a CD-RW or a CD-DA or a CD-
The gain for the reflected light information must be switched depending on whether it is R or not. Normally, a disc is placed on a disc tray pulled out of a disc drive device, and loaded into a recording / reproducing position (a pickup corresponding position) by storing the disc tray in the device. In such a case, the presence or absence of a disk must also be determined as part of the disk determination.

For this reason, in the conventional disk drive device, when the disk tray is stored, an operation of focusing the laser light on the disk is performed, and as a result, the first type disk (CD- DA or CD-R) or a second type disc (CD-R
W), or whether a disc is not loaded.

The operation procedure for this determination is as follows. First, a laser beam is output from the pickup as a reproduction power level, and an operation for focusing is performed. That is, a so-called focus search is performed in which the objective lens of the pickup is forcibly moved within a movable range, a focus pull-in range is searched, and a focus servo is turned on within the focus pull-in range to perform focusing. The reflected light information from the disc with respect to the laser output is subjected to arithmetic processing after being given a predetermined gain to generate a reproduction RF signal, a focus error signal, a tracking error signal, and the like. The gain (RF gain, servo gain) for the reflected light information is a gain corresponding to the first type of disc, CD-DA or CD-R. Note that, due to the difference in reflectance, the second type of disc (C
D-RW), a higher gain value is set.

First, as described above, a focus search is performed in a state of gain corresponding to the first type of disc. If the focusing operation can be performed up to three times to move the objective lens as the focus search, the focus search is performed. When the disc is a first-type disc (CD-DA or C-
DR).

If the focus cannot be pulled in even after performing the focus search three times, the gain is then switched to a value corresponding to the second type disc (CD-RW). Then perform a focus search and focus search up to 3
If the focus can be pulled in before the execution, the disc at that time is determined to be a second type disc (CD-RW). On the other hand, if the focus is not pulled in even after performing three focus searches (that is, a total of six focus searches), it is determined that there is no disc.

However, in such a discrimination method, the vertical movement of the objective lens as one focus search is about one.
Since the time is set to about 2 seconds, it is determined that the disk is about 1 to 3 seconds when it is determined to be the first type disk, about 4 to 6 seconds when it is determined to be the second type disk, and it is determined that there is no disk. In this case, it takes 6 seconds or more, and the determination process takes a very long time. That is, when a disc is loaded, the start-up process for recording / reproducing operation of the first or second kind of disc is delayed by a corresponding amount, and when no disc is loaded, more than 6 seconds Also perform useless operations.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in order to make it possible to quickly and accurately determine the type 1 disk, the type 2 disk, and the absence of a disk. Aim.

For this reason, the first type of disc whose proper gain value for the reflected light information to be read is the first gain value, and the second kind of disc whose proper gain value for the reflected light information to be read is the second gain value. As a disc drive device capable of performing recording or reproducing drive corresponding to each of the two types of discs, the objective means is set by the pickup means while the reflected light information processing means is set to the second gain value for the discriminating operation. The reflected light information of the laser light is detected while the lens is forcibly moved, and the level of the predetermined reflected light information signal output from the reflected light information processing means is determined during the objective lens movement period, so that the laser light is loaded. Discriminating means for discriminating whether the disc being loaded is a first-type disc or a second-type disc, or whether no disc is loaded Provided.

In other words, discrimination between the first and second types of discs in which the appropriate gain value differs depending on the difference in the reflectance is performed by setting the appropriate gain value to one of the types of discs. This is performed depending on whether or not the level of the optical information signal is in an appropriate state. That is, when the second gain value (a value higher than the first gain value) is set, if the loaded disc is a second type disc, the level of the reflected light information signal should be in an appropriate state. If the loaded disk is a first-type disk, the level of the reflected light information signal should be excessive, so that it can be determined based on the level. Further, if no disc is loaded, reflected light information cannot be obtained. That is, the level is zero, which is also not an appropriate state, and it can be determined that there is no disk from the level of the reflected light information signal.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
CD-DA and CD-R of the first kind and CD
A description will be given by taking a disk drive device corresponding to the second type of disk called -RW as an example.

FIG. 1 is a block diagram of the disk drive of the present embodiment. The disc D to be loaded is a CD-
DA, CD-R, or CD-RW. The disc D is loaded while being placed on a disc tray (not shown) and chucked on the turntable 7. When the user wants to load the disk D, the user performs an operation of pulling out the disk tray from the disk drive device housing (eject operation), pulling out the disk tray, placing the disk thereon, and storing the disk tray. I do. Then, the disk D is in a state of being chucked on the turntable 7 as shown. Therefore, when the disk tray is stored, there are cases where the disk is present as a first type disk and a second type disk when the disk exists.
Also, there is a possibility that the disc is not placed on the disc tray. For this reason, in this example, as will be described later, when the disc tray is stored, the discrimination between the first type disc, the second peripheral disc, and the absence of the disc is performed.

The loaded disk D is kept at a constant linear velocity (CLV) by the spindle motor 1 during a reproducing operation.
Alternatively, it is driven to rotate at a constant angular velocity (CAV). The pickup 1 reads data recorded on the disk D in the form of emboss pits or phase change pits.

The pickup 1 includes a CD-DA and a CD-DA.
An optical system suitable for R and CD-RW is provided. The laser diode 4 serving as a laser light source has, for example, a laser whose output has a center wavelength of 780 nm, and the objective lens 2 has, for example, NA = 0.45. The objective lens 2 is held by a biaxial mechanism 3 so as to be movable in the tracking direction and the focus direction of the disk D. The entire pickup 1 can be moved in the disk radial direction by a sled mechanism 8.

As a reproducing operation by the pickup 1, information on the reflected light from the disk D is detected by the detector 5 and is converted into an electric signal corresponding to the amount of received light and supplied to the RF matrix amplifier 9. The RF matrix amplifier 9
It includes a current-voltage conversion circuit, an amplification circuit, a matrix operation circuit, and the like. After performing current-voltage conversion and amplification processing on the signal from the detector 5, various necessary signals are generated by the operation processing. For example, it generates an RF signal as reproduction data, a focus error signal FE for servo control, a tracking error signal TE, and the like.

The amplification circuit in the RF matrix amplifier 9 performs a process of giving a predetermined gain to the voltage value as the reflected light information. Are different from each other depending on whether the disc is a second type disc. That is, before the recording / reproducing operation on the disc D is performed, the disc type is discriminated in the discrimination processing described later, so that the gain G1 for the first disc or the gain G2 for the second disc is set.

Here, C, which can be used as a disk D,
FIG. 2 briefly shows the difference between the characteristics of D-DA, CD-R, and CD-RW. The first kind of disc, C
The reflectivity of D-DA and CD-R is about 70%, and the gain for reflected light information, that is, the gain G1 set by the amplifier circuit in the RF matrix amplifier 9 described above.
Is a value corresponding to a reflectance of about 70%. On the other hand, the reflectivity of a CD-RW of the second type is about 20%, so that the gain G2 for the reflected light information is set higher than the gain G1. For example, the gain G2
Is about 13 dB higher than the gain G1. In addition,
Regarding the spindle control, in a read-only CD-DA, a pit synchronization method is used in which the pit data to be reproduced is synchronized. On the other hand, a recordable / reproducible CD-R, CD-RW is formed as a track guide groove. A groove synchronization method is used in which information on the groove is synchronized.

The reproduced RF signal generated by the RF matrix amplifier 9 is supplied to a binarizing circuit 12 and a new discriminating correct answer path 14, and a focus error signal FE and a tracking error signal TE are supplied to a servo processor 31.

The reproduction R obtained by the RF matrix amplifier 9
The F signal is converted into a so-called EFM signal (8-14 modulated signal) by being binarized by the binarization circuit 12,
Supplied to In the decoder 13, EFM demodulation, CIRC
The information read from the disk D is reproduced by performing decoding, deinterleaving, and the like.

The servo processor 11 calculates various servos of focus, tracking, thread and spindle from the focus error signal FE and tracking error signal TE from the RF matrix amplifier 9 and the spindle error signal SPE from the decoder 13 or the system controller 10. Generate a drive signal and execute a servo operation.

That is, a focus drive signal according to the focus error signal FE and the tracking error signal TE,
Generates a tracking drive signal and generates a two-axis driver 18.
To supply. The two-axis driver 18 drives the two-axis mechanism 3 in the pickup 1. Thus, the pickup 1, the RF matrix amplifier 9, the servo processor 11,
A tracking servo loop and a focus servo loop by the two-axis driver 18 are formed.

The servo processor 11 sends a spindle error signal SP to the spindle motor driver 19.
The spindle drive signal generated according to E is supplied. The spindle motor driver 19 applies, for example, a three-phase drive signal to the spindle motor 6 according to the spindle drive signal, and causes the spindle motor 6 to perform CLV rotation. In addition, the servo processor 11 generates a spindle drive signal in response to a spindle kick / brake control signal from the system controller 10, and causes the spindle motor driver 19 to start or stop the spindle motor 6.

The servo processor 11 generates a thread drive signal based on, for example, a thread error signal obtained from a tracking error signal TE or the like, an access execution control from the system controller 10, and supplies the thread drive signal to the thread driver 17. The sled driver 17 drives the sled mechanism 8 according to the sled drive signal, so that the pickup 1 can be properly slid.

The laser diode 4 in the pickup 1 is driven by a laser driver 20 to emit laser light. When performing laser emission, the system controller 10
Generates power control data for instructing read or write power, and the value of the power control data is D /
The voltage is converted into an analog voltage by the A converter 22 and supplied to the automatic power control circuit 21. The auto power control circuit 21 performs laser emission driving based on the supplied voltage value, thereby realizing laser emission with read power or write power.

Various operations such as servo and decoding as described above are controlled by a system controller 30 formed by a microcomputer. For example, operations such as reproduction start and end, track access, fast forward reproduction, and fast reverse reproduction are realized by the system controller 30 controlling operations of the servo processor 31 and the pickup 1.

Since the device is compatible with both the first type disk and the second type disk, when there is a possibility that the disk D is loaded (that is, when the disk tray is stored), the disk D It is necessary to determine the type or detect the absence of a disk. For proper recording / reproducing operation, the RF
It is necessary to switch the gain (set G1 or G2).

In this example, a discrimination signal generation circuit 14 is provided for discriminating the type and presence / absence of the disc D, and the system controller 10 controls the first type disc and the second disc based on the discrimination signal DD from the discrimination signal generation circuit 14. Discrimination between two types of discs and no disc is performed. The discrimination signal generation circuit 27 is provided with an A / D converter 15 for converting a reproduced RF signal (sum signal) into digital data, and a discrimination processing unit 16 for discriminating a level of the reproduced RF signal converted into digital data. I have. The determination operation performed by the determination signal generation circuit 14 and the system controller 10 will be described with reference to FIGS.

As is well known, the objective lens 2 in the pickup 1 is moved toward and away from the disk D by a focus servo operation so that the laser beam is focused on the signal surface of the disk D. To execute the focus servo control, first, the objective lens 2 is forcibly moved within the focus stroke range, and the focus pull-in range is detected. That is, an S-shaped curve is observed as the focus error signal FE, and a focus search operation for searching for a focus pull-in range that is a linear area of the S-shaped curve is performed. Then, by turning on the focus servo loop in a state where the objective lens is located in the focus pull-in range, focus servo control that subsequently converges to the just focus state is executed.

In the process of loading the disk D and performing the start-up operation for recording or reproduction, such a focus search and focus servo operation are performed together with the spindle motor speed setting, and the tracking servo is turned on. It is said. Here, in this example, just before the focus search operation, the objective lens 2 is forcibly moved within the focus stroke range similarly to the focus search, and the reproduction RF signal obtained during this time is observed, thereby obtaining the first type. The disc is determined to be a disc, a second kind disc, or no disc.

FIG. 3 shows a process performed by the system controller 10 as this determination process. The disc tray is stored (that is, there is a possibility that the disc is loaded)
And the processing of the system controller 11 proceeds to step F10.
From 1 the process proceeds to step F102 to start the discrimination process.
In step F102, first, the laser output with the read power from the laser diode 4 is started, and the spindle motor 6 is started.

Subsequently, in step F103, the RF matrix amplifier 9 is set to set the RF gain to the gain G2, that is, the gain corresponding to the second type disk. Then, in step F104, a forced movement operation of the objective lens 2 similar to the focus search is started. That is, the servo processor 11 generates a focus search voltage for forcibly moving the objective lens 2 with the focus servo loop off, and the two-axis driver 18
Is applied to the focus coil. FIG. 4A shows the focus drive signal.
The focus drive signal at 0 to t1 is a drive signal generated by the processing in step F104, that is, in this case, the objective lens 2 has a focus stroke (search range) from the position farthest from the disk D, It will be moved to the closest position.

At time t1 when the movement in the search range is completed, the process proceeds from step F105 to F106, and disc discrimination is performed. This disc discrimination is processing for confirming the discrimination signal DD from the discrimination signal generation circuit 14 as described above. The determination signal generation circuit 14
At times t0 to t1, the reproduced RF signal is fetched as digital data, and each signal level in that period is determined. Since the RF gain is set to G2 in step F103, if the loaded disk D is a type 2 disk having a low reflectance, the reproduced RF signal is output from the objective lens as shown in FIG. An appropriate signal amplitude is obtained when 2 passes through the focal point. A / D converter 1
Assuming that the resolution of No. 5 is 256 (FFh) and the peak of the appropriate RF signal corresponds to about half the level of 80 h, a level near 80 h is observed as the peak level as the signal amplitude. At this time, an S-shaped curve in an appropriate level range is observed as the focus error signal FE in FIG. 4B.

On the other hand, if the disk D is a first type disk having a high reflectivity, the gain G2 has an excessively large gain value. Therefore, as shown in FIG. When passing through the focal point, an excessive signal amplitude is obtained, and the output of the A / D converter 15 is a saturated value (FF
h). At this time, an S-shaped curve in an excessive level range is observed as the focus error signal FE in FIG. 4B.

Further, if no disk is loaded, the reflected light cannot be obtained as a matter of course.
As shown in (e), the reproduced RF signal remains at the zero level at time points t0 to t1. Of course, as shown as the focus error signal FE in FIG.
No curve is observed.

The discrimination processing section 16 generates a discrimination signal DD from the RF signal level according to the disc type and presence / absence. As a specific example, a peak value is determined for a sample value that has been captured by A / D conversion, and a reliable value (a value excluding abnormal values due to noise or the like) is determined as the peak value. The first type and the second type are discriminated based on whether they are within the range (for example, whether the threshold is about A0h or not), and when there is almost no reliable peak value, it is discriminated that there is no disk. I do.

Further, a window signal for discrimination is generated by comparing the reproduced RF signal with a predetermined threshold value, such as a signal indicating a section where the S-shaped curve is observed (so-called FOK signal), and the window period is determined. The first type disk, the second type disk, and the absence of the disk may be determined by observing the max value in the above.

In this embodiment, the discrimination signal generating circuit 14 discriminates the disc at the level of the reproduced RF signal (sum signal). However, as shown in FIG. 4B, the discrimination signal generation circuit 14 changes the level of the focus error signal FE. The determination can also be made by checking.

The discrimination signal generation circuit 14 supplies a discrimination signal DD as a discrimination result of the first disc, the second disc, and the absence of the disc to the system controller 11, and the system controller 11 confirms this in step F106. If no disc is loaded as a result of the determination, the process of the system controller 11 proceeds to step F1.
The process proceeds from 07 to the end process of F111. That is, the laser output is turned off, the spindle rotation is stopped, and the operation is completed.

If the discrimination result indicates that the disc is a second type disc, the process proceeds from step F108 to F110 to directly start the focus search process. That is, the objective lens 2 is returned to the farthest position from the time point t1 to the time point t2 in FIG. 4A, and the objective lens driving as a focus search is executed from the time point t2. Then, for example, when the focus pull-in range is detected at time t3, the focus servo is turned on, and pull-in to the in-focus position is performed. Thereafter, processing such as tracking servo ON is performed, and the processing shifts to processing such as reproduction / recording.

When the discrimination result indicates that the disc is a type 1 disc, the process proceeds from step F108 to F109, where the set gain in the RF matrix amplifier 9 is first changed to the gain G
Switch to 1. Then, the process proceeds to step F110 to start the focus search process. That is, FIG.
The objective lens 2 is returned to the farthest position from the time t1 to the time t2, and the objective lens driving as a focus search is executed from the time t2. At this time, since the gain has been switched to the gain value G2 corresponding to the type 1 disc, a reproduction RF signal and a focus error signal at appropriate levels can be obtained. Then, at time t3 when the S-shaped curve is observed as the focus error signal FE, the focus servo is turned on to perform the pull-in to the in-focus position. After that, processing such as tracking servo on is performed, and playback /
Move to processing such as recording.

As described above, in this example, before executing the focus search, the gain G2 is set as the gain for the reflected light information, and the objective lens is driven in the same manner as in the focus search. The type 1 disk, the type 2 disk, and the absence of the disk are determined from the level. Therefore, in any state, the discrimination can be performed within the time (for example, about 1 second) as the objective lens movement period of one focus search stroke, and it is determined that there is no disc as in the conventional example. It is not necessary to execute the focus search stroke movement a number of times until the focus search stroke moves. In particular, when the determination is made based on whether or not the focus can be turned on as in the conventional example, it is possible to avoid the focus pull-in failure due to disturbance or the like to avoid the determination by one movement of the objective lens. In the present example, the reproduction RF signal was observed during the moving period of the objective lens, and the discrimination was performed based on the difference in signal level that appeared due to the difference in reflectance. Since it is performed, it can be reliably and accurately determined during one objective lens movement.

Since the discrimination process can be executed quickly and accurately as described above, the start-up process for the reproduction and recording operations can be speeded up, and unnecessary operations can be eliminated when no disc is used. As an embodiment, CD-DA, C
Although a disk drive apparatus compatible with DR and CD-RW has been described as an example, the present invention can be applied to disk drive apparatuses using other disks. In other words, the disc drive apparatus is suitable for discrimination processing as a disc drive apparatus that can handle a plurality of types of discs having different reflectivities.

In the above example, the discrimination processing is performed after setting the gain G2. However, the discrimination can be performed by setting the gain G1. In this case, if the disk D is a type 1 disk, the peak value of the reproduced RF signal is 80
h, on the other hand, if the disk D is a second type disk, the peak value of the reproduced RF signal is considerably smaller than 80h. In addition, when there is no disk, the peak value is almost zero. Therefore, the setting of the threshold value for discrimination must be stricter than in the above example, but the discrimination itself is possible.

[0046]

As described above, in the disk drive of the present invention, the reflected light of the laser beam is forcibly moved while the objective lens is forcibly moved with the second gain value corresponding to the second type of disk set. By detecting information and determining the level of a predetermined reflected light information signal output from the reflected light information processing means during the objective lens movement period, whether the loaded disk is the first type disk or not is determined. Since the discrimination is made as to whether the disc is the same type of disc or the disc is not loaded, the discrimination process can be performed very quickly and accurately, which is only one moving period of the objective lens in the focus stroke. There is an effect that can be performed. In addition, this makes it possible to realize a de-drive device having a quick start-up operation, and has a further advantage that the discrimination of the absence of a disc is speeded up, so that useless operation when no disc is loaded can be eliminated.

[Brief description of the drawings]

FIG. 1 is a block diagram of a disk drive device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of characteristics of a disk to which the disk drive device according to the embodiment corresponds.

FIG. 3 is a flowchart of a discrimination process of the disk drive device according to the embodiment.

FIG. 4 is an explanatory diagram of discrimination processing of the disk drive device according to the embodiment;

[Explanation of symbols]

1 pickup, 2 objective lens, 2 biaxial mechanism, 4
Laser diode, 5 detector, 6 spindle motor, 7 turntable, 8 thread mechanism, 9
RF matrix amplifier, 10 system controller,
11 servo processor, 12 binarization circuit, 13 decoder, 14 discrimination signal generation circuit, 15 A / D converter,
16 Discrimination processing unit

Claims (5)

[Claims] A first type disc having an appropriate gain value for the reflected light information to be read as a first gain value;
As a disk drive device capable of performing a recording or reproducing drive corresponding to each of the second type disks in which the appropriate gain value for the reflected light information to be read is set to the second gain value, A pickup means for irradiating laser light with the objective lens as a laser output terminal and detecting reflected light information; and a switchable setting between the first gain value and the second gain value, The reflected light information processing means for performing amplification processing with the gain value set for the reflected light information, and further performing various required arithmetic processing to output various reflected light information signals, While the objective lens is forcibly moved by the pickup means in a state where the second gain value is set, the reflected light of the laser light Information is detected, and the level of a predetermined reflected light information signal output from the reflected light information processing means is determined during the moving period of the objective lens to determine whether the loaded disk is a first type disk. A disc drive device comprising a discriminating means for discriminating whether the disc is of two types or a disc is not loaded. 2. The disk drive device according to claim 1, wherein the predetermined reflected light information is a light amount signal of reflected light from a disk. 3. The disk drive device according to claim 1, wherein the second gain value is higher than the first gain value. 4. A disc of a second type, wherein the level of the predetermined reflected light information is within an appropriate level range.
If the level of the predetermined reflected light information is higher than the appropriate level range, the first type disc is not loaded. If the level of the predetermined reflected light information is lower than the proper level range, no disc is loaded. 4. The disk drive according to claim 3, wherein the discrimination is made. 5. A first-type disc in which an appropriate gain value for read reflected light information is a first gain value,
A disk drive device capable of performing a recording or reproducing drive corresponding to each of the second type disks in which an appropriate gain value for the reflected light information to be read is set to a second gain value higher than the first gain value. In the disk discrimination method of the above, in a state where the gain for the detected reflected light information is set to the second gain value, the reflected light information of the laser light is forcibly moved while the objective lens which is the laser output end of the pickup means is forcibly moved. Is detected, and the level of a predetermined reflected light information signal output during the objective lens movement period is determined to determine whether the loaded disk is the first type disk or the second type disk. Alternatively, a disc discriminating method comprising discriminating whether a disc is not loaded.